Urine Cytology
Under normal conditions. urine contains a small number of cells and other particulate matter shed from the entire length of the urinary tract. These materials are usually known as urinary sediments. Typical urinary sediments consist of red blood cells, white blood cells, epithelial cells, casts, mucus and crystals. In addition, sporatic urinary sediment such as bacteria, yeast, parasites and spermatozoa occur in patients suffering from various types of disorders or engaging in particular activities. Examination of urinary sedimentation is a routine procedure in urinalysis. With disease, these cells as well as other biologically formed elements are often increased and may help to localize the site and type of injury. For example, excessive numbers of red blood cells may indicate tumor, stones or inflammation. Excessive number of leukocytes may indicate infection or other inflammatory disease. In contrast to the hypocellular nature of normal urine, neoplastic cells (e.g., transitional, squamous and columnar cells) are shed more frequently in malignant conditions of the bladder epithelium.